Skip to content
Heist/ feed
Back to feed
MediumFix available

bouncycastle — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2020-26939

In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

Products
bouncycastle
Affected versions
Not specified
Fixed versions
1.61-1
CVEs
CVE-2020-26939
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 13:45 UTC · Revision 1

Source evidence

DEBIAN-CVE-2020-26939

core-osv · Original source

Published 2 Nov 2020, 22:15 UTC

In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

osv:DEBIAN-CVE-2020-26939

bouncycastle

Fixed versions: 1.61-1

bouncycastle

Fixed versions: 1.61-1

bouncycastle

Fixed versions: 1.61-1

Complete source record
{
  "id": "2ee8467c8a163604c1c8a59108b518fb9e7c8f7cb83f77b84fdd54b6764afb32",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-26939",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2020-26939",
    "summary": "In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.",
    "evidence": "osv:DEBIAN-CVE-2020-26939",
    "products": [
      {
        "name": {
          "value": "bouncycastle",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.61-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "bouncycastle",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.61-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "bouncycastle",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.61-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2020-26939",
      "aliases": [
        "DEBIAN-CVE-2020-26939"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.61-1"
                }
              ]
            }
          ],
          "package": {
            "name": "bouncycastle",
            "purl": "pkg:deb/debian/bouncycastle?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26939.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.61-1"
                }
              ]
            }
          ],
          "package": {
            "name": "bouncycastle",
            "purl": "pkg:deb/debian/bouncycastle?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26939.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.61-1"
                }
              ]
            }
          ],
          "package": {
            "name": "bouncycastle",
            "purl": "pkg:deb/debian/bouncycastle?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26939.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-26T12:02:41.469943272Z",
      "provider": "osv",
      "upstream": [
        "CVE-2020-26939"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2020-26939"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2020-26939",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 452770,
  "published_at": "2020-11-02T22:15:13.393+00:00"
}